I. Field of the Invention
This invention relates to earth moving equipment which is adapted to be hitched to and pulled behind a tractor. More specifically, the present invention relates to a tractor drawn land arranger having the capability to scrape, level, dig, and carry.
II. Description of the Prior Art
The prior art discloses several types of tractor drawn earth shaping machines. Examples of these machines are disclosed in U.S. Pat. Nos. 1,911,511 to Jordan, 2,483,033 to Baker, 3,110,972 to Waite, and 3,651,589 to Reynolds. The patent to Jordan discloses a tractor drawn device including a frame having a hydraulically actuated scoop operable to either scrape, scoop, or dump dirt. The problem associated with the Jordan device is that the scoop has a limited range of operation, and is forced to function in an inferior manner. Specifically, the Jordan scoop can only level dirt after it is itself full to the point of refusal. As such, the scoop unavoidably removes a substantial amount of dirt before scraping can occur. Such a system leads to problems during operation because it can become a guessing game as to when scraping, as opposed to scooping, will occur, and in some instances the scoop will merely become a heavy dragged object accomplishing neither scooping or scraping. Such guess work often leads to trial and error operation when using the device in unfamiliar soil, and can produce poor results.
The Baker device is a scoop adapted to be mounted on the front of an earth moving implement equipped with a blade. The blade is positioned so as to push dirt into the scoop for carrying and later deposition as desired. The scoop cooperates with the blade and tractor earth moving capability to add a dirt carrying capability previously not associated with the bulldozer.
The Waite device is a tractor drawn earth scooping and carrying device. The scoop includes a frontal shroud portion which prevents scooped earth from exiting the device while in the transport mode. Also, the scoop can be substantially tipped so as to empty the scoop. However, the Waite device is disadvantaged in a manner similar to the Jordan device in that simple scraping cannot be accomplished without some guess work. Instead of simply scraping and moving a layer of dirt in front of a blade, a certain amount of scooping and carrying may take place which will lessen the scraping effect of the blade.
The patent to Reynolds reveals a tractor drawn scraper wherein the angle of inclination of the bucket or scoop can be adjusted somewhat in order to spread dirt collected evenly and smoothly. However, the inventive hydraulic system in this patent is such that the bucket may only be lowered while it is in its horizontal or loading position. Consequently, it becomes difficult to perform controlled scraping and levelling without also scooping and collecting dirt in the bucket.